As a technology relative to copy machines, there has been proposed a copy method that starts printing without completion of reading of a document in order to reduce a time from start of the reading to completion of the printing. In this specification, this print mode to start printing without waiting for completion of reading of a document is referred to as a “preceding print mode”. Meanwhile, the print mode to start printing after completion of reading of a document is referred to as a “memory print mode”.
For example, there has been disclosed a technology of selecting a compression scheme according to the type of a copy command, compressing data of a read document according to the selected compression scheme, and determining a print start timing according to the compression scheme in a copy machine for performing a preceding print mode.